How to fish in the story of New Eternal Dragon Slayer?

White fish in cold pool

Dig a few more times under the upper left corner of the yard to get earthworms, then raise a bamboo branch, and combine bamboo branches, earthworms, fishing lines and hooks to get baited fish. When equipped, fish on the big stone on the right side of the pond in the bamboo branch diagram for a few times until you catch white fish.